"When fathers are actively involved with their children, children do better," Paul Amato, a sociologist who studies parent-child relationships at Pennsylvania State University, told Fatherly. "All of this research suggests that fathers are important for a child's development."

If that sounds like a no-brainer, rest assured that it is not. Research on fatherhood and the downstream effects of engaged, thoughtful dad-ing is scant, relative to the extensive literature on motherhood. Strange as it may sound, fatherhood is an emerging field of study. But there's a race underway to make up for lost time. Almost daily, scholars are now releasing new data that illustrates how men can both help and hurt their children. Some of these results — ugly divorces aren't great for kids — are relatively logical. Others are not. One wouldn't necessarily guess that the correlation between a fatherly presence and lack of aggression would be consistent across class. It is. One wouldn't assume dad staying home would be negatively correlated to female delinquency. It is.

"The Father Effect" is the umbrella term for the benefits of a paternal presence. These effects can be numerous when fathers actively participate in family life. "There needs to be a minimum amount of time spent together, but the quality of time is more important than the quantity of time," Amato says. "Just watching television together, for example, isn't going to help much."

Fortunately, it seems that this is what modern fathers want and, in a broader sense, what society expects of them. When we were expecting our son, it was essentially a given that I, the father, would take a hands-on role from pregnancy through birth (and beyond, obviously). I didn't blink when my wife asked me to attend a birthing class with her, and, as a matter of fact, there were few pregnant bellies in the room that weren't accompanied by anxious, aspiring dad bods. The question of whether I would be involved in the labor was never even raised — it was simply a matter of how close I wanted to be to the action. And for the baby's first diaper change, the nurses dutifully passed the tarry black baton to me. It felt both squishy and natural.

It wasn't always thus. That's why the emerging consensus on the importance of fathers during every stage of a child's development is worth monitoring. Scientists are studying, on some level at least, a new phenomenon. Their findings support a conclusion that might change how we parent.

It starts with sperm

Sperm and egg. Shutterstock

Fathers are more than just sperm donors, but that doesn't mean one can discount the importance of sperm. There is perhaps no greater and more universal Father Effect than genetic information.

First of all, some parents are inevitably going to pass genetic diseases onto their kids. One way to mitigate that and decrease the odds of passing along the most debilitating diseases is to seek genetic counseling before conceiving, especially if you're a member of a high-risk group.

But for everyone else, there's epigenetics — the study of changes in DNA that are caused by lifestyle choices, the environment, and other outside factors. While we tend to blame mothers for ruining the genetic information in their eggs with drugs and alcohol, until recently we had little concept of how fathers' vices might impact their sperm. We now know that the decisions a man makes before conception can have lifelong impacts on his kids. Studies suggest that men who drink before conception are more likely to have sons who abuse alcohol, and that poor dietary choices in men can lead to negative pregnancy outcomes. At least one study suggests that men who are stressed before conception may predispose their offspring to high blood sugar.

"We know the nutritional, hormonal, and psychological environment provided by the mother permanently alters organ structure, cellular response and gene expression in her offspring," said Joanna Kitlinska of Georgetown University, who ran a study on the subject in 2016, in a statement. "But our study shows the same thing to be true with fathers—his lifestyle, and how old he is, can be reflected in molecules that control gene function."

Great fathers are incubated

Until the 1960s, experts seldom encouraged dads to take part in parent groups, to participate during labor, or to care for infants. It was generally understood that dads existed to teach their toddlers to walk and their kids to play catch, not to handle baby — or, gasp, pre-baby — stuff. But the past few decades of research suggest that the earlier a dad gets involved, the better. In a 1997 book on the subject, researchers argued that fathers who are actively involved in labor are effectively developing relationships (albeit one-way relationships) with their children as early as possible, and subsequent studies suggest this leads to stronger early attachment to the baby.

Whether early attachment to a baby breeds more serious involvement in the long-term is a matter of debate, but there's plenty of evidence that it does. In a 2011 literature review on paternal involvement during pregnancy and labor, the authors claim that the preponderance of evidence suggests that dads who are actively involved and invested in the baby before he or she is born disproportionately remain involved in the child's life. And, as numerous studies have shown, more paternal involvement means better outcomes for kids. To foster this connection, some scientists have argued that healthy women and newborns should return home as soon as possible after delivery, especially if the father is not allowed to stay overnight in the hospital.

This is not to say that fathers play a critical role in the development of fetuses — after their initial epigenetic contribution, they're down for the count until after delivery. But pregnancy and labor are when the groundwork for the Father Effect begins, and its importance cannot be overstated.

What we talk about when we talk about engaged fathers

Before we dive into how involved fathers help their kids (and how uninvolved fathers harm them), it's important to highlight what an engaged, active, involved father looks like. First of all, as ever, showing up is half the battle. Dads who live with their kids and take time out of their days to attend important events are far more likely to have a positive impact than absent fathers.

For dads who live apart from their kids, there are limited options for engaging fatherly interactions. "Writing letters, phone calls — even if you're not in physical proximity, knowing your dad cares and wants to be involved to the extent that they can is really important," Marcy Carlson, a sociologist at the University of Wisconsin, told Fatherly. If you can't even do that, buying love isn't the worst idea. "There's tons of evidence that financial support of kids is good for their outcomes," she says. "If dads can provide for their children, that goes a long way."

But just because you're around doesn't mean you can rest on your laurels and hope that sitting near your children will somehow raise their IQs or inoculate them against risky sexual behaviors. "The quantity of interaction doesn't really benefit kids, but if you have more high-quality, engaged parenting that does seem to be positively related to outcomes for children," Carlson says. Warmth is also a key factor. Fathers who spent a lot of time with their kids but are dismissive or insulting tend to have only negative impacts.

"Low quality fathering can involve behaving coldly toward one's children, insulting them, or engaging in problem behaviors that are largely incompatible with being a present and engaged father," Danielle DelPriore, a developmental psychologist at the University of Utah, told Fatherly.

Why your infant (and toddler) needs a dad

As a science-oriented person, I try not to be unrealistic about what my toddler understands. Although it pains me to admit it, I understand that he probably doesn't miss me much when I travel for work, and I know that he lights up in my presence in pretty much the same way he lights up for puppies, apples, and rice cakes. This is frustrating for me, and I'm not alone. There's a reason that fathers often find themselves wondering why they should even bother investing time and energy into infants who, for at least another couple of years, won't care or remember.

(Although the trend holds across several studies, it is important to note that at least one studydid not find a link between fathers playing with their infants and cognitive development).

When infants transition into toddlers at around age one, Father Effects become even more pronounced. Studies suggest that when fathers are involved in everyday tasks — dinner, playing in the backyard — rather than expansive but one-off trips, toddlers and young children benefit. Dads also seem to offer a unique touch, with at least one study suggesting that fathers are better than mothers at teaching children how to swim, because they are less overprotective and more likely to let their children venture into the deep end or swim facing away from them.

As anecdotal evidence indicates, sons especially need their dads. In the book Do Fathers Matter? Paul Raeburn describes how scientists observed that U.S. and Norwegian boys whose fathers were off fighting in World War II during their childhoods later had trouble forging relationships with others as they matured. Similar studies cited in the book show that sons who grow up without fathers (or with disengaged fathers) tend to be less popular in preschool. Broadly, the research suggests that boys lean on their fathers more than anyone else as they develop social skills. And one large study of nearly 9,000 adults confirmed that a father's death affects sons more strongly than daughters, leading to the same sort of health problems seen after an ugly divorce.

In other words, kids — even very young kids — need their dads. And, despite conventional wisdom (and its underpinning sexism), daughters need them too. But for different reasons.

Why your daughter needs a dad

Father and daughter. Shutterstock

Most studies suggest that, until children hit puberty, the Father Effect is roughly equal for boys and girls. Both boys and girls who are fortunate enough to have dads in their lives excel and, in some cases, outperform their peers. But when raging hormones kick in, studies demonstrate that dads suddenly become the arbiters of sexual behavior, too. And that is most acutely felt by teenage daughters, who take fewer sexual risks if they have strong relationships with their dads.

"Numerous past studies find a link between low quality fathering and daughters' sexual outcomes, including early and risky sexual behavior," Danielle DelPriore, who has studied how dads impact risky sex, told Fatherly. "A father who is cold or disengaged may change daughters' social environments and sexual psychology in ways that promote unrestricted sexual behavior."

One of DelPriore's studies on the phenomenon — or "daddy issues", as it is popularly portrayed — tracked 101 sister pairs between the ages of 18 and 36. This was a particularly well-controlled study, because it allowed DelPriore and her colleagues to examine how two women with similar genetics who were raised under similar environmental conditions might differ in their sexual risk-taking. She found that, when one sister grew up with an active, warm father and the other was raised in a broken home or after their father became less engaged, the former grew up to largely avoid casual unprotected sex while the latter often embraced it. Although DelPriore examined several outside factors — including relationships with mothers — one of the most salient links between a woman and her sexual decision-making was how close she felt to her father.

DelPriore suggests that daughters might learn from disengaged fathers that they shouldn't expect men to invest meaningfully in long-term relationships, and so they settle for riskier casual flings. It's also possible that "daughters with disengaged fathers receive less parental monitoring and are more likely to affiliate with sexually promiscuous friends," she says. "On the other hand, having a father who is warm and engaged can protect against these outcomes."

DelPriore defined "engaged fathers" as those who behave warmly and interact meaningfully with their kids. They're the sort of dads who help with homework and attend sporting events, seldom insulting their children or behaving coldly. "When it comes to daughters, taking the time to listen to them, learn about their lives, show up for important events, and provide emotional support, could protect against early and unrestricted sexual behavior," she says. "Dads do not have to be perfect, and making a genuine effort to be there for their daughters could make a big difference."

What happens when Dad disappears

Children who lose a father to death or incarceration suffer much like those who have uninvolved fathers and represent an easier community to study than the abandoned.

Several research projects have focused on how a father's incarceration can harm children. The largest of these efforts is Princeton University's Fragile Families Study, which is currently following a cohort of 5,000 children born in the United States between 1998 and 2000. Most of the children in the study have unmarried parents and absentee fathers, for a variety of reasons. One of the most sobering findings of the FFS is that, when a dad is behind bars or otherwise far away, there is relatively little he can do to have a positive influence on his children.

"For dads that live far away, it doesn't seem there's tons of evidence that what they do matters for their children," Carlson told Fatherly. "Dads living with their kids are much more involved; they read stories to their children and put their kids to bed. If you look at comparisons of resident and non-resident dads, there's a consistent difference in average involvement."

When dads are absent due to prison sentences, kids face additional challenges — sometimes more serious ones than what they would have faced had their fathers died or left due to divorce. "Most of the literature on widowhood shows that kids whose dads died are better off than kids who go through divorce," she says. As for incarceration "there's a lot of stigma and stress. I wouldn't be surprised if it's worse for kids when their dads are away due to incarceration."

How to be a good dad

A lot goes into being a solid father. Making healthy decisions before conceiving so that your kid has the best shot in life, genetically speaking. Coaching your partner through pregnancy and birth so that your bond to your child starts early. Playing with your infant even though he'll never remember. Counseling your teenage daughter about making smart choices. But those are the mechanical parts of fatherhood. In a more general sense, these studies all emphasize the importance of not just parenting, but parenting well — not just being present and doing what the studies suggest, but legitimately caring for your children and modeling good behavior.

Perhaps most importantly, dads need to realize that their kids are always watching, and that what they do matters. How well a dad parents influences a child's psychological, cognitive, and social development, and strongly steers him or her toward adulthood. Because dads do matter.

"Fathers and mothers are children's most important teachers," Amato says. "Fathers might ask themselves, what are my children learning — about life in general, about morality, about how family members should treat one another, about relationships — from observing me every day?"